I’m having an issue with your solution for the green triangle. You seem to be using 5cm as the measurement for it’s base, but that would create an equilateral triangle with two radii and the center of the circle. But the angle at the center would be 48 degrees (2*(360/12)), so it can’t be equilateral. The base of the green triangle I make to be 5sin48/sin66. Which would make the height the root of 83.5 (ish), not 5root3.

I’m struggling to find where I’ve gone wrong, any ideas?

I really like ALL these problems and they will fit well into the new SoW I’m writing for KS3 and KS4 – thank you very much.

So glad you find them useful. ðŸ™‚

I’m having an issue with your solution for the green triangle. You seem to be using 5cm as the measurement for it’s base, but that would create an equilateral triangle with two radii and the center of the circle. But the angle at the center would be 48 degrees (2*(360/12)), so it can’t be equilateral. The base of the green triangle I make to be 5sin48/sin66. Which would make the height the root of 83.5 (ish), not 5root3.

I’m struggling to find where I’ve gone wrong, any ideas?

2*360/12 is 60 not 48. try doing it without trigonometry it’s a bit more elegant